The use of modular assemblies permits the manufacture of families of products using a common base, each personalised by different options or functions, notably complications in the case of a mechanical timepiece movement.
The concept of extremely high precision modules or sub-assemblies allows large scale production to be combined with high quality goods.
Thus, modular sub-assemblies for timepiece movements are known, from EP Patent Application Nos. 11193173.9 and 11193174.7 in the name of ETA SA. The mechanical modules disclosed in these Patent Applications are irreversibly pre-adjusted and assembled to ensure the durability of their settings.
However, in a conventional embodiment, the modules do not always allow for a reduction in the number of components, which would both reduce production costs and simplify the assembly plan, enabling mid-level technical personnel to assemble and adjust the most complex functions.
CH Patent No 447042 in the name of TISSOT discloses a device for securing the outer end of a balance spring, including a rigid support comprising projecting studs between which the balance spring is threaded in a sinuous path, and held laterally by an overlapping portion comprised in one of the studs.
EP Patent Application No 2151722A1 in the name of ROLEX discloses a balance spring with at least two coplanar strips wound with an offset capable of neutralising the lateral forces likely to be exerted on the central arbour when one of the ends of each strip is angularly shifted about the arbour, relative to the other end of the strip. In a variant, the strips are joined to each other by their respective two inner and outer ends.
EP Patent Application No 2347126A1 in the name of ROLEX discloses a balance spring wherein the outer end of a strip of the balance spring is fabricated integrally with a member for connection to the timepiece frame, the rigidity of this connecting member being greater than that of the spring. The connecting member and the frame have complementary bearing surfaces.